Dmitri Ivanovich Blokhintsev (11.01.1908 — 27.01.1979) was a Soviet theoretical physicist and a corresponding member of the USSR Academy of Sciences (1958) and of the Academy of Sciences of the Ukrainian SSR (1939). He was born in Moscow. He graduated from Moscow University (1930). He taught there (professor from 1936, and later head of the department of theoretical nuclear physics). In 1935—47 he also worked at the Physical Institute of the USSR Academy of Sciences. In 1947 he was director of a research laboratory in the town of Obninsk, on the basis of which the Institute of Physics and Power Engineering was created under his direction, and in 1950—56 he was its director. In 1956—65 he was director of the Joint Institute for Nuclear Research (Dubna), and from 1965 of the Laboratory of Theoretical Physics at that institute.
His research concerned the theory of solids, semiconductor physics, optics, acoustics, quantum mechanics and quantum electrodynamics, nuclear physics, the theory of nuclear reactors, quantum field theory, the physics of elementary particles, and philosophical and methodological questions of physics. He explained the phosphorescence of solids on the basis of quantum theory, and the rectification of electric current at the boundary between two semiconductors. In 1944 he constructed a theory of acoustic phenomena in moving and inhomogeneous media, obtaining the equations of acoustics in their most general form. He carried out one of the first studies in nonlinear optics; in particular, he developed the theory of the Stark effect in a strong alternating field and studied nonlinear effects.
A considerable place in Blokhintsev's scientific work is taken by his research on the theory and the engineering problems of nuclear chain reactions and nuclear reactors. He did much for the development of Soviet atomic science and technology. He directed the design and the construction of the first nuclear power station, which came into operation in 1954 (Lenin Prize, 1957). He developed effective methods of calculating reactors operating on slow, intermediate and thermal neutrons. Together with A. I. Leipunsky he provided the scientific direction of the development of the concept and the design of the first fast-neutron reactor with a liquid-metal coolant in Europe. He put forward the idea (1955) of pulsed fast reactors and built the IBR-1 (1960) and the IBR-2 (commissioned 1981).
From 1956 Blokhintsev's scientific interests were concentrated on the physics of elementary particles. His research here was in the field of the structure of elementary particles, the limits of applicability of quantum electrodynamics, questions of the interaction of high-energy particles, nonlocal field theory, and problems connected with the concepts of space and time in the microworld. As early as 1938 he predicted the “Lamb shift”. He proposed ideas about fluctuations in the density of nuclear matter (1957), about quantum stochastic spaces, and about the existence of several vacua and of spontaneous transitions between them; he pointed out the existence of the so-called unitary limit, developed the theory of the confinement of ultracold neutrons and more.
Hero of Socialist Labour (1956). USSR State Prizes (1952, 1971). A member of a number of academies of sciences and scientific societies. In 1966—69 he was president of the International Union of Pure and Applied Physics.